Dementia, including Alzheimer's disease (AD), is a common and devastating neurodegenerative disorder of the elderly. Most older individuals receive their health care solely within the general practice/primary care setting. Dementia, and complications related to dementia, will impose growing demands on the general practice sector as the US population ages. Few data exist on the occurrence, characteristics, and outcomes of dementia in the U.S. general practice setting. Such data cannot be obtained or extrapolated either from specialty clinics/case-control studies or from community surveys. Using a clinical epidemiological approach, we propose to examine the prevalence, outcomes, and prognostic factors in Alzheimer's and other dementias in an elderly general practice (internal medicine/family practice) patient population drawn from a stable, biracial, economically depressed community in Southwestern Pennsylvania. Screening all patients aged 65+ seen over one year (anticipated N=6,240) within five participating practices, we will evaluate them for the presence of AD/dementia and related variables. We will estimate their prevalence and describe their characteristics. We will then follow them for four years to assess outcomes of interest (mortality, institutionalization, and complications of dementia) and to identify prognostic factors for the outcomes. Prognostic (risk and protective) variables to be examined will include subjects' demographic, clinical, and relevant social characteristics, as well as selected medical interventions. Results will shed important new light on the prevalence, type, and severity of dementia in general practice, as well as its impact on long-term outcomes. Such clinical epidemiological data are needed to determine the risks associated with dementia in primary care patients. They will also assist in formulating appropriate policies and guidelines for early diagnosis, treatment, and prevention of excess disability.